Collision prevention system for vehicles

ABSTRACT

The invention relates to a system for preventing collisions of an automobile with obstacles. Sensors mounted in the automobile detect the area surrounding the vehicle. The signals of said sensors are evaluated by a data processing device in order to calculate the available obstacle-free driving space. Other sensors additionally detect the position of all movable vehicle parts (e.g. a trailer) and the dynamic parameters of the current driving situation (e.g. speed, steering angle, etc.). Based on said data, the driving speed required during the following time intervals in order to continue driving is calculated in advance by the data processing device and compared with the actually available obstacle-free driving space that has been detected. Said comparison provides early forecast regarding a possible collision. The driver is warned of a possible collision danger by corresponding warning devices and can consequently react in time. In critical situations (e.g. high driving speed), direct interventions in the control of the vehicle by the data processing device can take place to assist the driver.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The invention is concerned with the field of automotive engineering. In particular, the invention relates to safety systems for preventing collisions.

[0003] 2. Description of the Related Art

[0004] Such systems are specifically significant for vehicles which are less easy to steer into critical situations owing to their size, their weight and to a certain extent complex design (for example, a plurality of axles, trailers, containers, etc.).

[0005] These vehicles are, for example, trucks (rigid vehicles, semitrailers and trailer vehicles), buses, articulated vehicles and other vehicles (for example recreational trailers), in which the problem arises that existing overhangs in various regions of the vehicle (rear, front, corner edges and superstructures) swing out when turning and maneuvering. In addition, depending on the type of vehicle, a plurality of regions of the vehicle cannot usually be satisfactorily seen from the driver's position so that owing to “dead angles” the driver is frequently unable to monitor swinging out—for example by looking in the mirror—and notice, for example, during a maneuver, when such regions of the vehicle are coming too close to obstacles, and react appropriately. As a result, in tight driving situations there is a risk of colliding with obstacles and other road users, which may result in serious injury to persons and severe damage to property.

[0006] Typical situations in which the described problems occur are presented below:

[0007] a) Risk of Collisions in the Front Region

[0008] In particular, vehicles with a large front overhang (distance between front axle and the front of the vehicle) swing out a very long way when turning or maneuvering and must also move out to a great extent in very narrow streets. As a result, the front of the vehicle moves over a correspondingly large radius, and in particular side regions of the front can quickly impact against obstacles (see FIG. 1). Even when reversing in order to park or performing reversing maneuvers, the front of the vehicle moves in a circular arc shape (locked front wheels) so that there is also the risk of side regions of the front being involved in a collision (see FIG. 2). This risk is increased further as when reversing the main attention of the driver is of course directed at the rear region of the vehicle in accordance with the direction of travel.

[0009] b) Risks of Collisions in the Rear Region

[0010] In a corresponding way, in the case of vehicles with a large overhang at the rear (distance between the rear axle and rear), there is a risk of collision specifically of the side regions of the rear both when performing maneuvers moving forward and when performing reversing maneuvers (see FIGS. 3 and 4). In particular in the case of vehicles with trailers, semi-trailers or superstructures (for example a vehicle-mounted rotational crane) these risks of collision are particularly pronounced.

[0011] c) Risks of Collision with Attached Trailers, Semi-Trailers, etc.

[0012] Specific problems arise in vehicles with trailers, semi-trailers or superstructures. In such vehicles, the front of the attached part of the vehicle swings out in the form of an arc when turning or maneuvering in the forward direction and reverse direction so that there is a risk of collision in critical driving situations (see FIGS. 5, 6, 7).

[0013] d) Risk of Collision of the Side Regions of a Vehicle

[0014] The side regions of a (relatively long) vehicle can also collide with obstacles in a small maneuvering space (see FIGS. 8 and 9).

[0015] The situations described show that the problems of preventing collisions as comprehensively as possible are relatively complex. Systems in which distance messages are issued are known. In such systems, the critical regions of a vehicle are monitored by devices (for example ultrasonic sensors, video cameras) which sense when obstacles are approached. When a predefined distance from the obstacle is undershot, the driver is warned, for example, by means of optical or audible signals. However, these systems can detect obstacles and distances in good time only in simple driving situations. For this reason, owing to the vehicle's own movement, warnings are issued too late (or incorrectly) so that as a result of the, under certain circumstances, high chronological dynamics of the driving situation, there is hardly the possibility any more for the driver to react appropriately in good time.

SUMMARY OF THE INVENTION

[0016] The invention takes this prior art as a starting point. It is based on the object of developing an improved system for preventing vehicles from colliding with obstacles.

[0017] This object is achieved by means of the method as claimed in claim 1 and the apparatus for carrying out the method having the features of claim 8. Further details and advantageous refinements emerge from the subclaims.

[0018] The present invention is described in more detail below, and in this context

[0019]FIG. 10 shows schematic views of the required driving space using the example of a tight bend in a chronological sequence (t₀, t₁, t_(n)).

[0020]FIG. 11 is an illustration of the existing driving space of the same situation according to FIG. 10.

[0021]FIG. 12 shows a comparison of the required driving space and existing driving space in accordance with the driving situation at the time t₁ (according to FIG. 10).

DETAILED DESCRIPTION OF THE INVENTION

[0022] The system according to the invention for preventing collisions detects situation parameters which are different at a particular time so that the risk of a collision can be sensed in good time. On the basis of this, collision-preventing measures are then taken. The operation of the system can be divided here into individual regions:

[0023] a) Determination of the Required Driving Space

[0024] A significant component of the system is to determine the required driving space, which differs depending on the maneuver. The required driving space is the volume in space which is “passed through” in chronological succession as the vehicle travels. This includes, in particular, also the space which is required when turning and maneuvering as a result of the swinging out of overhangs. FIG. 10 shows in schematic exemplary form the spatial positions of a truck at the times t₀, t₁, t_(n) while going through a tight bend. By incrementally superimposing the chronological sequence of the positions it is thus possible to illustrate the total driving space required for the driving maneuver.

[0025] In order to avoid collisions, the system according to the invention determines sections of the required driving space chronologically in advance from various data items by calculation in a data processing device (computer, microprocessor).

[0026] These data items are, on the one hand, the dimensions of the vehicle including the dimensions of further parts of the vehicle, such as trailer, semitrailer, superstructures, etc. In addition to the size information there are structural details (position of axles, position of the support point, etc. of the trailer coupling, etc.) as these also determine the moving out of parts of the vehicle.

[0027] In addition to these (generally constant) values, information relating to the instantaneous position of moving parts of a vehicle (steering angle, angle between the trailer and traction engine, etc.) which changes during the journey and therefore has to be continuously updated is required. In order to acquire this data, appropriate sensors (measuring sensors, position pickups, etc.) have to be present on the vehicle and their signals have to be passed on to the data processing device.

[0028] An essential factor for preventing a collision is to calculate in advance as precisely as possible the driving space which is required in future (for further travel). For this purpose, in addition to the aforesaid data, various dynamic values of the driving situation (speed, shifting of gear speed, engine speed, brake values, etc.) also have to be acquired and included in the calculations. For the continuous sensing of these dynamic values, appropriate sensors whose data is transferred to the data processing device are necessary.

[0029] The required driving space which is taken up by the vehicle (including parts of the vehicle) when the travel continues is then calculated as a function of all this data.

[0030] b) Determination of the Existing Driving Space

[0031] The existing driving space is a spatial region without obstacles which is available for the vehicle to travel safely without collisions. This driving space is generally determined by the road profile and is additionally restricted by immovable obstacles (road boundaries, trees, houses, parked vehicles, etc.), and on the other hand is changed by moving obstacles and road users (vehicles, pedestrians, etc.). Depending on the events on the road, the existing driving space changes here more or less dynamically. FIG. 11 shows this situation of an existing driving space which changes over time (t₀, t₁, t_(n)).

[0032] In order to prevent collisions, the dimensions of the existing driving space must be determined and included in calculations of the data processing device. For this purpose, initially the spatial surroundings of the vehicle have to be sensed. Various means are used for this, for example, GPS (Global Positioning System), digital maps (stored in the data record of the data processing device or capable of being retrieved by a wire-free connection to fixed computers), optical and other radiation sensors (visible light, infrared, radar), distance and movement sensors (for example ultrasonic sound, laser, etc.). In conjunction with video cameras, it is also possible to use modern techniques for recognizing images (computer evaluation of video signals for recognizing objects) in order to identify obstacles. For complex sensing of surroundings as precisely as possible, a plurality of the specified means are preferably combined here. The data which is supplied by these devices is transmitted to the data processing device and evaluated there in order to calculate the dimensions of the existing driving space. Thus, a virtual image can be created, for example as a grid model of the existing driving space.

[0033] As, on the one hand, the position of the existing driving space changes continuously whenever the vehicle itself moves, and on the other hand the dimensions can also change as a result of moving obstacles, this calculation of the existing driving space has to be continuously updated. Depending on the current speed of the driver's own vehicle but also of other moving obstacles (for example oncoming passenger cars), it may be necessary for the time interval t₁−t₀ between two successive occasions when the changing existing driving space is sensed to be in the region of a fraction of a second.

[0034] c) Predicting Collisions by Comparison of Required Driving Space and Existing Driving Space

[0035] In order to detect at an early point an imminent collision, a comparison is carried out between the previously calculated required driving space and the existing driving space which is actually sensed at a given time. This comparison is carried out by means of corresponding calculations by the data processing device. If the required driving space which is calculated in advance exceeds the limits of the existing driving space there is a risk of a collision, that is to say whenever the vehicle (including parts of the vehicle such as trailers, etc.) is in the process of leaving the existing driving space if the journey continues without change.

[0036] As the driving situation (position of the vehicle, moving obstacles, etc.) changes continuously, these comparison calculations over time (t₀, t₁, . . . t_(n)) are repeated continuously with updated data relating to the existing driving space or required driving space. Ideally, continuous monitoring for a collision is carried out during the entire journey.

[0037] As numerous measurement processes during which inaccuracies may also occur, are carried out by means of a number of different sensors in order to sense both the required driving space and the existing driving space, it is necessary to carry out the collision forecasting calculated from this data with safety regions relating to the spatial conditions and their change over time. For example, the required driving space which is calculated in advance can be enlarged with safety distances and/or the sensed existing driving space can be correspondingly reduced. Depending on the dynamic development of the driving situation (locomotion of the driver's own vehicle, changes in position of other road users) these safety distances can also be adapted dynamically.

[0038] All the necessary calculations can be carried out in the vehicle itself by means of an appropriately powerful on-board data processing device. Alternatively, the signals of the detectors and sensors which are located on the vehicle can be transmitted for calculation purposes via a wire-free connection to a fixed data processing system and after evaluation there the results can be transmitted back to the vehicle where the corresponding reaction is then triggered. A combined system is also possible in which a first data processing system in the vehicle is connected in wire-free fashion to a fixed data processing system.

[0039] d) Preventing Collisions

[0040] If there is a risk of collision, the system carries out a series of measures according to an incremental catalog of measures. If there is sufficient time to prevent the collision through customary driving maneuvers, warning signals which cause the driver to intervene are appropriate at first. These warning signals may be issued audibly (striking sounds/tones but also through voice outputs, in which case specific instructions, for example relating to the place on the vehicle in question or else action recommendations are also possible), optically (for example, by means of light), visually (for example, by means of graphic representations of the vehicle and the obstacle on appropriate displays), or else haptically (for example, a vibration, shaking of the steering wheel). If the remaining time is not sufficient for an appropriate reaction by the driver, the system brings about a direct intervention in the control of the vehicle, for example, emergency braking or counter-steering of the vehicle in order to return to the existing driving space. Furthermore, the size of the required space may be reduced by automatically reducing the contours of the vehicle (for example, folding in the side mirrors, retracting the antennas, lowering spoilers, etc.; changing the ride control, in order to reduce the height of the vehicle before an underpass/bridge or in order to increase the floor clearance; adjusting the superstructures and overhangs, for example retracting the tailgate, turning crane superstructures at bends, adjusting the length of the drawbar).

[0041] The system according to the invention provides a high degree of reliability in preventing collisions as not only the current distance values between parts of the vehicle and obstacles is taken into account, but also dynamic changes are sensed and used for a calculation in advance so that a collision warning can be issued before critical distances are reached in the first place. This early warning generally permits collisions to be prevented through normal driving maneuvers, i.e. interventions by the driver may be made without excessively hasty actions during which there is always the risk of an incorrect reaction (elimination of the so-called reaction time).

[0042] In addition to this important aspect of a relatively early warning indication, the system according to the invention can additionally provide the driver with valuable information (for example anticipated location of a collision, current distance from the obstacle, remaining time, etc.), which significantly reduces the reaction time further as the driver can intervene directly in an entirely targeted fashion. This support is particularly advantageous in unclear situations (unfavorable light conditions, for example due to fog, driving area with poor visibility, high traffic volume, etc.) in which the potential risk of a collision is correspondingly high. As not only the driver's own changes in position are taken into account, but also the continued movement of other road users is detected, it is possible, for example, even to detect an imminent collision which is not brought about by the driver's own movement (under certain circumstances even in a stationary state) but rather for example as a result of another vehicle approaching.

[0043] In addition to the described warning and notification function, the system can be configured in such a way that it actively supports the driver in making difficult maneuvers (narrow course of a road, bridges, and the like). Such help may consist, for example, in the fact that movable parts of a vehicle which are at risk of a collision are automatically removed (swung away, folded in, lowered, etc.) from the area of risk during maneuvering by the system intervening. The driver is thus largely relieved of the need to perform these various actuation processes. Wider-ranging interventions in order to provide support in carrying out maneuvers in spatially restricted conditions are also possible. For example, given an appropriate configuration the system can, for example, actively change the maneuvering properties of the vehicle (ride control, adjustment of the length of the drawbar, etc.).

[0044] In one preferred embodiment to the system according to the invention, the system intervenes directly in the control of the vehicle (steering, brake etc.) in driving situations with critical timing. This provides additional security in situations in which human reaction times are no longer sufficient.

[0045] The described system for preventing collisions provides the advantage that it can relatively easily be adapted to changes, for example, in the contours of a vehicle (for example new trailer, different superstructures etc.). Such changes can be incorporated into the system without a large degree of technical expenditure in that the corresponding data relating to the new dimensions is simply input into the memory of the (mobile and/or fixed) data processing system. Given an appropriate embodiment, this can also be carried out, for example, in a wire-free fashion. If there are frequently repeated (identical) changes (for example, traveling with a loaded or unloaded container), a plurality of different contours or dimensions of the vehicle may also be contained in the memory of the data processing system and retrieved.

[0046] The system according to the invention is defined by a large field of use as it is suitable for a very large range of types of vehicle for preventing collisions: for example passenger cars with recreational trailers, articulated trucks, construction site vehicles (concrete mixers, vehicle-mounted cranes, excavator transporters) as well as agricultural vehicles and other utility vehicles. 

1. A method for preventing a vehicle colliding with obstacles, distance values between the vehicle and obstacles in the surroundings being sensed and the driving space which is available being calculated from these distance values, values relating to the current movement (speed, direction of travel, deceleration etc.) of the vehicle being additionally sensed and the driving space which is required to continue the journey being calculated from these values in conjunction with values of the dimensions of each vehicle, a comparison between the existing driving space and required driving space being subsequently carried out, and measures for preventing collisions being initiated when the required driving space extends beyond the existing driving space, characterized in that the values of the dimensions of the veh Abt-Fulrad-StraBe 4icle are read out of a memory, which is configured in such a way that a plurality of different vehicle contours can be stored in it.
 2. The method as claimed in claim 1, characterized in that the values of the dimensions of the vehicle can be transmitted in wire-free fashion into the memory of the data processing system.
 3. The method as claimed in one of claims 1 or 2, characterized in that, in addition to the dimensions of the vehicle, the structural properties of the vehicle (the position of the axles, support and length of the drawbar, etc.) which also determine the driving behavior (for example turning circle, swinging out of protuding or carried parts, etc.) can be included in the calculation of the required driving space.
 4. The method as claimed in one of claims 1 to 3, characterized in that in the case of moving vehicle parts (for example trailers) information relating to the current position of these vehicle parts (for example obliquely positioned drawbar) is included in the calculation of the required driving space.
 5. The method as claimed in one of claims 1 to 4, characterized in that the required driving space and existing driving space are calculated at time intervals (t₀, t₁, t₂, . . . ), these intervals following one another in such brief succession that changes to the existing driving space (for example caused by movement of other vehicles) and of the required driving space (for example as a result of braking or changing of direction of the vehicle) are sensed with appropriate speed so that measures initiated when there is a risk of collision prevent a collision.
 6. The method as claimed in one of the preceding claims, characterized in that a spatial safety distance between the vehicle and obstacles is included by virtue of the fact that correspondingly reduced dimensions of the existing driving space and/or enlarged dimensions of the required driving space are used to carry out the comparison.
 7. The method as claimed in one of the preceding claims, characterized in that the measures initiated to prevent collisions may include the triggering of warning signals (optical, audible, visual or haptic), a change in the dimensions of the vehicle (for example as a result of external mirrors folding in, the retraction of spoilers, swinging out of crane superstructures etc.) changes in the maneuverability of the vehicle (for example, as a result of ride control, changing the length of the drawbar, etc.), intervening in the control of the vehicle (for example steering, brakes, shifting of gears).
 8. The method as claimed in one of the preceding claims, characterized in that the measures for preventing collisions are initiated in a sequence which is determined by the chronological proximity of a collision.
 9. An apparatus for preventing a vehicle colliding with obstacles, having means for sensing distance values between vehicle components and obstacles in the surroundings of the vehicle, means for sensing movement parameters of the vehicle (speed, direction of travel, deceleration, etc.), the existing driving space being calculated from the distance values by means of a data processing system, the driving space which is required to continue driving being additionally calculated from the movement parameters in conjunction with values of the dimensions of the vehicle, and a comparison between the existing driving space and required driving space being carried out, devices being present which, in the case of a calculated expansion of the required driving space beyond the existing driving space, are actuated by the data processing system in order to prevent a collision, characterized in that a memory which is configured in such a way that a plurality of different vehicle contours can be stored in it is provided for storing the values of the dimensions of the vehicle.
 10. The apparatus as claimed in claim 9, characterized in that the apparatus has a communications unit by means of which the values of the dimensions of the vehicle can be transferred into the memory of the data processing system in a wire-free fashion.
 11. The apparatus as claimed in one of claims 9 and 10, characterized in that the data processing device also includes, in the calculation of the required driving space, information relating to the structural properties of the vehicle (position of the axles, support and length of the drawbar, etc.) which also determine the driving behavior of the vehicle (for example, turning circle, swinging out of protruding or carried parts, etc.).
 12. The apparatus as claimed in one of claims 9 to 11, characterized in that there are means which, in the case of moving parts of vehicles (for example trailer), sense the current position of these parts of vehicles (for example obliquely positioned drawbars) and these values are included in the calculation of the required driving space by means of the data processing system.
 13. The apparatus as claimed in one of claims 9 to 12, characterized in that the data processing system determines the required driving space and existing driving space at time intervals (t₀, t₁, t₂, . . . ), these intervals following one another in such short succession that changes to the existing driving space (for example caused by movement of other vehicles) and to the required driving space (for example due to braking or a change in direction of the vehicle), are sensed with appropriate speed so that the devices for preventing a collision are actuated by the data processing system at such an early time that a collision is prevented.
 14. The apparatus as claimed in one of the preceding claims 9 to 13, characterized in that a spatial safety distance between the vehicle and obstacles is included by virtue of the fact that, before the comparison is carried out, the data processing system reduces the dimensions of the existing driving space by computational means and/or increases the dimensions of the required driving space.
 15. The apparatus as claimed in one of the preceding claims 9 to 14, characterized in that the devices for preventing a collision may include means for triggering warning signals (for example optical, audible, visual, haptic), means for changing the dimensions of the vehicle (for example by folding in external mirrors, retracting spoilers, swinging out crane superstructures, etc.), means for changing the maneuverability of the vehicle (for example ride control, changing the length of the drawbar, etc.), means for intervening in the control of the vehicle (for example steering, brakes, shifting of gears).
 16. The apparatus as claimed in one of the preceding claims 9 to 15, characterized in that the devices for preventing a collision are actuated by the data processing system in a sequence which is determined by the chronological proximity of a collision.
 17. The apparatus as claimed in one of the preceding claims 9 to 16, characterized in that the means for sensing distance values between parts of a vehicle and obstacles are embodied as optical (for example infrared), or audible (for example ultrasonic) distance measuring sensors or as radiation sensors (radar, laser), or as video cameras or as electronic devices for determining position/surroundings (GPS).
 18. The apparatus as claimed in one of the preceding claims, characterized in that that the data processing system is carried in the vehicle as a mobile system.
 19. The apparatus as claimed in one of the preceding claims, characterized in that the vehicle is connected to a stationary data processing system via a wire-free connection. 